A universal meter, either an electronic type or a mechanical type, typically have a function selector which can be turned manually to a particular angular position to select the measurement item and range as required. However, the selection often depends on an estimation about what is to be measured and how much it is. Erroneous selection will lead to an erroneous result in the measurement and, particularly in the measurement of high voltage and current, will bring a danger to the operator as well as to the meter itself.
Auto-measuring universal meters that can be used without selection are available now. Although such meters are easy to be operated, they can measure only voltage and resistance except current.
Therefore, there is a need for the improvement of the auto-measuring universal meter to overcome the shortcomings of the prior art.